1. Field of the Invention
The invention is directed to the field of connecting device for the electrically conductive connection of electronic components and at least one substrate, and, in particular, to such a connecting device formed as a film composite.
2. Description of the Related Art
Many connecting devices for electronic components are known. In the case of packaged components, by way of example, metallic connecting devices and the connection thereof to substrates by soldering are known. “Substrates” in this context are also to be understood to include printed circuit boards.
The use of wire bonding connections is widespread as a connecting device in the case of unpackaged components. Positively locking connections are also utilized, as so-called pressure contact-connections, in the area of power semiconductor modules. Likewise from power semiconductor modules, pressure-contact-connected flexible printed circuit boards are known connecting devices. German Patent Application No. DE 102 21 970 A1 discloses a power semiconductor module comprising a connecting device of this type, but does not disclose the exact structure thereof.
German Patent Application No. DE 103 55 925 A1 discloses a connecting device for power semiconductor components comprising a film composite of a first and a second electrically conductive film with an insulating interlayer therebetween. The power semiconductor components are permanently securely electrically connected to the first conductive layer by ultrasonic welding. In that case, the module-internal circuitry-conforming connection of the power semiconductor components to conductor tracks of a substrate is formed by means of metallic contacts whose thickness is adapted to that of the power semiconductor components. These contacts are connected to the connecting device by ultrasonic welding in the same way as are the power semiconductor components.
In that case, the conductive film for the ultrasonic welding connection to power semiconductor component and contact elements preferably comprises aluminum with embossing bumps, since aluminum forms an excellent welding connection with the metallization of the power semiconductor component. The metallization likewise comprises a final layer of aluminum.
What is disadvantageous in such arrangements, however, is that soldering connections with the aluminum layer are not possible, or are possible only to a very limited extent. Forming the corresponding layer of copper, which has a higher specific conductivity and is solderable, is not disclosed in the art, since a copper layer is not suitable for a welding connection to power semiconductor components.